1. Field of the Invention:
The present invention relates to a slip casting device for manufacturing sanitary ceramic articles.
2. Description of the Relevant Art:
Shaped sanitary ceramic articles, typically flush toilets, are generally manufactured by the slip casting method.
According to the slip casting method, a slip prepared by mixing clay powder with a sufficient amount of water is poured into a mold of either plaster or a water-permeable porous plastic material. The mold absorbs the added water, and the clay is built up on the inner shaping surface of the mold, producing a solid casting which has the inner shape of the mold.
If only a small number of shaped sanitary ceramic articles are to be produced, then molds are assembled manually, the slip is poured into the molds. The molds are subsequently left as they are for a while, and then split to obtain solid castings. Since the cast items thus formed still have a relatively high water content, they are dried, coated with a glaze, and fired.
If shaped sanitary ceramic articles are to be mass-produced, some or most of the above manufacturing steps should preferably be mechanized. One such mechanized slip casting method is disclosed in Japanese Laid-Open Patent Publication No. 58-208005 published Dec. 3, 1983. According to the disclosed slip casting method, upper and lower mold members which are heavy are assembled, clamped, and disassembled to release a cast product, all automatically so that the burden on the worker who handles the slip casting device is minimized. The upper and lower mold members are vertically separable from each other, with the upper mold member being fixed in position by a support post.
When the casting is to be removed from the mold, the lower mold member is separated downwardly while the casting is being attracted under suction by the upper mold member. Then, a feed pallet for supporting the bottom of the casting is moved from one side to a position below the casting. Therefore, the vertical dimension of the slip casting device is relatively large.
Since the upper mold member is fixed in position, it is necessary that the mold members be assembled, the slip be poured, the clay be built up, the extra slip be discharged, the mold be split, and the cast item be released, all in one location. During the slip casting process, particularly when the casting is released, the water and slip flowing out of the mold tend to fall over various device components below the mold. It is difficult to place a simple receptacle for receiving the water and slip below the mold because a complex mechanism for vertically moving the lower mold member is already disposed beneath the mold. As a result, a relatively complex arrangement is required to discharge the water and slip from the mold.
The slip casting device which carries out the disclosed method is complex in structure since the series of operations is effected in one place.
Recently, it has been proposed to tilt or swing the mold in its entirety in order to discharge the slip from the mold cavity efficiently after the clay has been built up on the inner surface of the mold. However, it is impossible to employ the proposed process in the slip casting device disclosed in the above publication since the upper mold member is fixed to the support post which is stationary.
The present invention has been made in an effort to effectively solve the aforesaid problems of the conventional slip casting device.